java - Cannot add to layout constraints must be a gridbagconstraint -

i need use gridbaglayout below error. can please help?

java.lang.illegalargumentexception: cannot add layout: constraints must gridbagconstraint @ java.awt.gridbaglayout.addlayoutcomponent(unknown source) @ java.awt.container.addimpl(unknown source) @ java.awt.container.add(unknown source) @ havuzaracıformu.(havuzaracıformu.java:221) @ havuzaracıformu$1.run(havuzaracıformu.java:47) @ java.awt.event.invocationevent.dispatch(unknown source) @ java.awt.eventqueue.dispatcheventimpl(unknown source) @ java.awt.eventqueue.access$500(unknown source) @ java.awt.eventqueue$3.run(unknown source) @ java.awt.eventqueue$3.run(unknown source) @ java.security.accesscontroller.doprivileged(native method) @ java.security.protectiondomain$javasecurityaccessimpl.dointersectionprivilege(unknown source) @ java.awt.eventqueue.dispatchevent(unknown source) @ java.awt.eventdispatchthread.pumponeeventforfilters(unknown source) @ java.awt.eventdispatchthread.pumpeventsforfilter(unknown source) @ java.awt.eventdispatchthread.pumpeventsforhierarchy(unknown source) @ java.awt.eventdispatchthread.pumpevents(unknown source) @ java.awt.eventdispatchthread.pumpevents(unknown source) @ java.awt.eventdispatchthread.run(unknown source)

import java.awt.borderlayout; import java.awt.eventqueue; import java.awt.font; import java.awt.gridbagconstraints; import java.awt.gridbaglayout; import java.awt.gridlayout;  import javax.swing.jframe; import javax.swing.jpanel; import javax.swing.border.emptyborder;  import org.jdatepicker.impl.jdatepanelimpl; import org.jdatepicker.impl.jdatepickerimpl; import org.jdatepicker.impl.utildatemodel;  import javax.swing.jlabel; import javax.swing.jtextfield; import javax.swing.jbutton; import javax.swing.jformattedtextfield.abstractformatter;  import java.awt.event.actionlistener; import java.sql.connection; import java.sql.drivermanager; import java.sql.resultset; import java.sql.sqlexception; import java.sql.statement; import java.text.parseexception; import java.text.simpledateformat; import java.util.calendar; import java.util.properties; import java.awt.event.actionevent;  public class havuzaracıformu extends jframe {      private jpanel contentpane;     private jtextfield textfieldadsoyad;     private jtextfield textfieldgorev;     private jtextfield textfielddepartman;      /**      * launch application.      */     public static void main(string[] args) {         eventqueue.invokelater(new runnable() {             public void run() {                 try {                     havuzaracıformu frame = new havuzaracıformu();                     frame.setvisible(true);                 } catch (exception e) {                     e.printstacktrace();                 }             }         });     }      /**      * create frame.      * @throws classnotfoundexception       * @throws sqlexception       */     public havuzaracıformu() throws classnotfoundexception, sqlexception {          setdefaultcloseoperation(jframe.exit_on_close);         setbounds(100, 100, 728, 992);         contentpane = new jpanel();         contentpane.setborder(new emptyborder(5, 5, 5, 5));         contentpane.setlayout(new gridbaglayout());         gridbagconstraints gbc = new gridbagconstraints();         gbc.gridx = 0;         gbc.gridy = 0;         gbc.fill = gridbagconstraints.horizontal;         gbc.anchor = gridbagconstraints.center;          setcontentpane(contentpane);          jlabel lblkullancbilgileri = new jlabel("kullan\u0131c\u0131 bilgileri");         font font = lblkullancbilgileri.getfont();         lblkullancbilgileri.setfont(new font(font.getfontname(), font.bold, 14));         contentpane.add(lblkullancbilgileri);                 jlabel lbladsoyad = new jlabel("ad\u0131 soyad\u0131");         jlabel lblgorevi = new jlabel("görevi");         jlabel lbldepartmani = new jlabel("departman\u0131");         contentpane.add(lbladsoyad,gbc);          textfieldadsoyad = new jtextfield();         contentpane.add(textfieldadsoyad, gbc);         textfieldadsoyad.setcolumns(10);          contentpane.add(lblgorevi);          textfieldgorev = new jtextfield();         contentpane.add(textfieldgorev, gbc);         textfieldgorev.setcolumns(5);          contentpane.add(lbldepartmani, gbc);          textfielddepartman = new jtextfield();         contentpane.add(textfielddepartman);         textfielddepartman.setcolumns(10);           jlabel lblaracbilgileri = new jlabel("araç bilgileri");         font font2 = lblaracbilgileri.getfont();         lblaracbilgileri.setfont(new font(font2.getfontname(), font.bold, 14));         contentpane.add(lblaracbilgileri, gbc);          jlabel lblmarka = new jlabel("marka");         contentpane.add(lblmarka, gbc);         jtextfield textfieldmarka = new jtextfield(5);         contentpane.add(textfieldmarka,gbc);         textfieldmarka.setcolumns(5);          jlabel lblmodel = new jlabel("model");         contentpane.add(lblmodel,gbc);         jtextfield textfieldmodel = new jtextfield();         contentpane.add(textfieldmodel,gbc);         textfieldmodel.setcolumns(5);          jlabel lblplakano = new jlabel("plakano");         contentpane.add(lblplakano,gbc);         jtextfield textfieldplakano = new jtextfield();         contentpane.add(textfieldplakano,gbc);         textfieldplakano.setcolumns(5);          jlabel lblcikistarihivesaati = new jlabel("Çıkış tarihi ve saati");         contentpane.add(lblcikistarihivesaati,gbc);         jtextfield textfieldcikis = new jtextfield(); //      contentpane.add(textfieldcikis);         utildatemodel model = new utildatemodel();         properties p = new properties();         p.put("text.today", "today");         p.put("text.month", "month");         p.put("text.year", "year");         jdatepanelimpl datepanel = new jdatepanelimpl(model, p);         jdatepickerimpl datepicker = new jdatepickerimpl(datepanel, new datelabelformatter());         contentpane.add(datepicker,gbc);          textfieldcikis.setcolumns(5);          jlabel lblcikiskm = new jlabel("Çıkış km");         contentpane.add(lblcikiskm,gbc);         jtextfield textfieldcikiskm = new jtextfield();         contentpane.add(textfieldcikiskm,gbc);         textfieldcikiskm.setcolumns(5);          jlabel lbldonustarihivesaati = new jlabel("dönüş tarihi ve saati");         contentpane.add(lbldonustarihivesaati,gbc);         jtextfield textfielddonus = new jtextfield();         utildatemodel model2 = new utildatemodel();         properties p2 = new properties();         p2.put("text.today", "today");         p2.put("text.month", "month");         p2.put("text.year", "year");         jdatepanelimpl datepanel2 = new jdatepanelimpl(model2, p);          jdatepickerimpl datepicker2 = new jdatepickerimpl(datepanel2, new datelabelformatter());         contentpane.add(datepicker2,gbc);         textfielddonus.setcolumns(5);          jlabel lbldonuskm = new jlabel("dönüş km");         contentpane.add(lbldonuskm,gbc);         jtextfield textfielddonuskm = new jtextfield();         contentpane.add(textfielddonuskm,gbc);         textfielddonuskm.setcolumns(5);          jlabel lblneden = new jlabel("aracın kullanılacağı yer-kullanım neden geçici araç");         contentpane.add(lblneden,gbc);         jtextfield textfieldneden = new jtextfield();         contentpane.add(textfieldneden,gbc);         textfieldneden.setcolumns(5);          jlabel lblkullanimsuresi = new jlabel("kullanım süresi");         contentpane.add(lblkullanimsuresi,gbc);         jtextfield textfieldsure = new jtextfield();         contentpane.add(textfieldsure,gbc);         textfieldsure.setcolumns(5);          jlabel lblhasarveeksiklikler = new jlabel("hasar ve eksiklikler");         contentpane.add(lblhasarveeksiklikler,gbc);          jlabel lblaractagorulenhasarlar = new jlabel("araçta görülen hasarlar veya eksiklikler (zincir, İstetme, İlk yardım Çantası vs.");         contentpane.add(lblaractagorulenhasarlar,gbc);          jtextfield textfieldhasar = new jtextfield();         contentpane.add(textfieldhasar,gbc);         textfieldhasar.setcolumns(5);          jbutton btnnewbutton = new jbutton("gönder");         btnnewbutton.addactionlistener(new actionlistener() {             public void actionperformed(actionevent arg0) {                 string url = "jdbc:sqlserver://win-j53h5bk2anc;databasename=test;integratedsecurity=true;";                 try {                     class.forname("com.microsoft.sqlserver.jdbc.sqlserverdriver");                  connection conn = drivermanager.getconnection(url);                 statement st = conn.createstatement();                 string querystring = "insert havuzaracıformu values ('" + textfieldadsoyad.gettext() + "'," +                                                                            "'" + textfieldgorev.gettext() + "'," +                                                                           "'" + textfielddepartman.gettext() + "'," +                                                                           "'" + textfieldmarka.gettext() + "'," +                                                                           "'" + textfieldmodel.gettext() + "'," +                                                                           "'" + textfieldplakano.gettext() + "'," +                                                                           "'" + datepicker.getjformattedtextfield().gettext() + "'," +                                                                           "'" + textfieldcikiskm.gettext() + "'," +                                                                           "'" + datepicker2.getjformattedtextfield().gettext()+ "'," +                                                                           "'" + textfielddonuskm.gettext() + "'," +                                                                           "'" + textfieldneden.gettext() + "'," +                                                                           "'" + textfieldsure.gettext() + "'," +                                                                           "'" + textfieldhasar.gettext() + "')";                 st.executeupdate(querystring);                 } catch (classnotfoundexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 } catch (sqlexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 }             }         });         contentpane.add(btnnewbutton, borderlayout.south);     }  }  class datelabelformatter extends abstractformatter{      private string datepattern = "yyyy-mm-dd";     private simpledateformat dateformatter = new simpledateformat(datepattern);      @override     public object stringtovalue(string text) throws parseexception {          return dateformatter.parseobject(text);     }      @override     public string valuetostring(object value) throws parseexception {         if(value != null){             calendar cal = (calendar) value;             return dateformatter.format(cal.gettime());         }         return "";     }  } 

once code formed simpler form compile without cruft, first line of stack trace relates custom (i.e. your) code is:

contentpane.add(btnnewbutton, borderlayout.south); 

borderlayout.south constraint meant borderlayout, earlier in code see..

contentpane.setlayout(new gridbaglayout()); // i.e. **not** borderlayout 

general advice

• see what stack trace, , how can use debug application errors? programmers see lot of exceptions throughout our careers, need learn how solve them, or @ least majority of them. when know how solve exceptions not sure why particular exception happening in particular line of code, should ask on so.
• as mentioned several people in comments, when in doubt, simplify code point error shows irrelevant code removed.
• the reason looked because bored , not sleep. i'd vote close , move on next problem person manage create mcve. ..don't rely on taking pity on in future.